Mark 9:11-13 NIV

11 And they asked him, "Why do the teachers of the law say that Elijah must come first?"
12 Jesus replied, "To be sure, Elijah does come first, and restores all things. Why then is it written that the Son of Man1 must suffer much2 and be rejected?3

References for Mark 9:12

13 But I tell you, Elijah has come,4 and they have done to him everything they wished, just as it is written about him."

References for Mark 9:13